Revision Question

1. What causes air pollution?

Air pollution is caused by emissions from vehicles, industrial processes, burning fossil fuels (coal, oil, natural gas), deforestation, and the use of chemicals.

2. How can we live sustainably?

By reducing waste, conserving energy, using renewable energy sources (solar, wind, hydropower, geothermal, biomass).

3. What causes changes in population growth rates?

Population growth is influenced by biological factors (birth and death rates), social factors (fertility rates, healthcare access), economic conditions, and cultural values.

4. What are the effects of high or low population growth?

• High population growth increases demand for resources, leads to habitat destruction, pollution, and strain on infrastructure.

• Low population growth can slow economic development and reduce workforce availability.

5. What are the three major roles of organisms in ecosystems?

• Producers: Create their own food through photosynthesis (e.g., plants).

• Consumers: Obtain energy by eating producers or other consumers (e.g., animals).

• Decomposers: Break down dead organic matter, recycling nutrients back into the soil (e.g., fungi, bacteria).

6. Why is biodiversity important?

It helps maintain ecosystem balance and supports natural processes.

7. What are two types of energy with examples?

• Renewable energy: Naturally replenished, e.g., solar power, wind energy.

• Non-renewable energy: Finite resources, e.g., coal, natural gas.

8. How do human activities contribute to air pollution?

By burning fossil fuels in transportation and industry, using chemical products, and deforestation.

9. What is air pollution?

Hazardous substances present in the atmosphere, including gases, particles, can harm human health, the ecosystem and the climate.

10. What are the effects of air pollution?

Air pollution damages plants, contaminates water, contributes to climate change, and causes respiratory problems in human health.

11. What are primary and secondary air pollutants?

• Primary pollutants: Emitted directly from sources (e.g., carbon monoxide, sulfur dioxide).

• Secondary pollutants: Formed in the atmosphere through chemical reactions (e.g., ozone, smog).

12. How does air pollution affect human health?

It can cause respiratory illnesses and increase mortality rates.

13. What is climate change and what causes it?

Climate change refers to long-term shifts in temperature and weather patterns, primarily caused by increased greenhouse gas emissions.

14. What greenhouse gases contribute to climate change?

Carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), and chlorofluorocarbons (CFCs).

These gases trap heat in the atmosphere and contribute to global warming.

15. What are the environmental impacts of greenhouse gases?

They trap heat in the atmosphere, causing global warming, melting ice caps, rising sea levels, and more frequent extreme weather events.

16. What are the main sources of water pollution?

Industrial discharge, agricultural runoff (pesticides, fertilizers), sewage, and chemical waste.

17. How can water pollution be prevented?

By reducing chemical use, treating wastewater, properly disposal of hazardous materials.

18. What types of solid waste exist?

• Municipal solid waste: Household and community waste (food scraps, paper, plastics).

• Industrial solid waste: Waste from manufacturing and industrial processes (chemicals, metals).

19. What happens to these types of solid waste?

Municipal waste is often landfilled or incinerated; industrial waste may require special treatment due to toxicity.

20. How can we reduce waste production?

Through sanitary landfills, composting organic waste, recycling materials, and reducing consumption.

21. Why are waste reduction methods important?

They minimize environmental pollution, conserve natural resources, reduce landfill use, and lower greenhouse gas emissions.